<?php
namespace core\lib;
/**
 * Cookie
 * @author wxuns
 * @link http://www.wxuns.cn
 * @since 2017年10月10日
 */
class Cookies{
	
	private $_prefix = '';                                                  // cookie prefix
	private $_securekey = 'ekOt4_Ut0f3XE-fJcpBvRFrg506jpcuJeixezgPNyALm';   // encrypt key
	private $_expire = 3600;                                                // default expire
	
	/** 初始化
	 * @param String $prefix     cookie prefix
	 * @param int    $expire     过期时间
	 * @param String $securekey  cookie secure key
	 */
	public function __construct($prefix='', $expire=0, $securekey=''){
		
		if(is_string($prefix) && $prefix!=''){
			$this->_prefix = $prefix;
		}
		
		if(is_numeric($expire) && $expire>0){
			$this->_expire = $expire;
		}
		
		if(is_string($securekey) && $securekey!=''){
			$this->_securekey = $securekey;
		}
		
	}
	/** 设置cookie
	 * @param String $name   cookie name
	 * @param mixed  $value  cookie value 可以是字符串,数组,对象等
	 * @param int    $expire 过期时间
	 */
	public function set($name, $value, $expire=0){
		
		$cookie_name = $this->getName($name);
		$cookie_expire = time() + ($expire? $expire : $this->_expire);
		$cookie_value = $this->pack($value, $cookie_expire);
		$cookie_value = $this->authcode($cookie_value, 'ENCODE');
		
		if($cookie_name && $cookie_value && $cookie_expire){
			setcookie($cookie_name, $cookie_value, $cookie_expire);
		}
	}
	/** 读取cookie
	 * @param  String $name   cookie name
	 * @return mixed          cookie value
	 */
	public function get($name){
		
		$cookie_name = $this->getName($name);
		
		if(isset($_COOKIE[$cookie_name])){
			
			$cookie_value = $this->authcode($_COOKIE[$cookie_name], 'DECODE');
			$cookie_value = $this->unpack($cookie_value);
			
			return isset($cookie_value[0])? $cookie_value[0] : null;
			
		}else{
			return null;
		}
	}
	/** 更新cookie,只更新内容,如需要更新过期时间请使用set方法
	 * @param  String $name   cookie name
	 * @param  mixed  $value  cookie value
	 * @return boolean
	 */
	public function update($name, $value){
		$cookie_name = $this->getName($name);
		if(isset($_COOKIE[$cookie_name])){
			$old_cookie_value = $this->authcode($_COOKIE[$cookie_name], 'DECODE');
			$old_cookie_value = $this->unpack($old_cookie_value);
			if(isset($old_cookie_value[1]) && $old_cookie_value[1]>0){ // 获取之前的过期时间
				$cookie_expire = $old_cookie_value[1];
				// 更新数据
				$cookie_value = $this->pack($value, $cookie_expire);
				$cookie_value = $this->authcode($cookie_value, 'ENCODE');
				if($cookie_name && $cookie_value && $cookie_expire){
					setcookie($cookie_name, $cookie_value, $cookie_expire);
					return true;
				}
			}
		}
		return false;
	}
	/** 清除cookie
	 * @param  String $name   cookie name
	 */
	public function clear($name){
		$cookie_name = $this->getName($name);
		setcookie($cookie_name);
	}
	/** 设置前缀
	 * @param String $prefix cookie prefix
	 */
	public function setPrefix($prefix){
		if(is_string($prefix) && $prefix!=''){
			$this->_prefix = $prefix;
		}
	}
	/** 设置过期时间
	 * @param int $expire cookie expire
	 */
	public function setExpire($expire){
		if(is_numeric($expire) && $expire>0){
			$this->_expire = $expire;
		}
	}
	/** 获取cookie name
	 * @param  String $name
	 * @return String
	 */
	private function getName($name){
		return $this->_prefix? $this->_prefix.'_'.$name : $name;
	}
	/** pack
	 * @param  Mixed  $data      数据
	 * @param  int    $expire    过期时间 用于判断
	 * @return
	 */
	private function pack($data, $expire){
		if($data===''){
			return '';
		}
		$cookie_data = array();
		$cookie_data['value'] = $data;
		$cookie_data['expire'] = $expire;
		return json_encode($cookie_data);
	}
	/** unpack
	 * @param  Mixed  $data 数据
	 * @return              array(数据,过期时间)
	 */
	private function unpack($data){
		if($data===''){
			return array('', 0);
		}
		$cookie_data = json_decode($data, true);
		
		if(isset($cookie_data['value']) && isset($cookie_data['expire'])){
			
			if(time()<$cookie_data['expire']){ // 未过期
				return array($cookie_data['value'], $cookie_data['expire']);
			}
			
		}
		return array('', 0);
		
	}
	/** 加密/解密数据
	 * @param  String $str       原文或密文
	 * @param  String $operation ENCODE or DECODE
	 * @return String            根据设置返回明文活密文
	 */
	private function authcode($string, $operation = 'DECODE'){
		
		$ckey_length = 4;   // 随机密钥长度 取值 0-32;
		
		$key = $this->_securekey;
		
		$key = md5($key);
		$keya = md5(substr($key, 0, 16));
		$keyb = md5(substr($key, 16, 16));
		$keyc = $ckey_length ? ($operation == 'DECODE' ? substr($string, 0, $ckey_length): substr(md5(microtime()), -$ckey_length)) : '';
		
		$cryptkey = $keya.md5($keya.$keyc);
		$key_length = strlen($cryptkey);
		
		$string = $operation == 'DECODE' ? base64_decode(substr($string, $ckey_length)) : sprintf('%010d', 0).substr(md5($string.$keyb), 0, 16).$string;
		$string_length = strlen($string);
		
		$result = '';
		$box = range(0, 255);
		
		$rndkey = array();
		for($i = 0; $i <= 255; $i++) {
			$rndkey[$i] = ord($cryptkey[$i % $key_length]);
		}
		
		for($j = $i = 0; $i < 256; $i++) {
			$j = ($j + $box[$i] + $rndkey[$i]) % 256;
			$tmp = $box[$i];
			$box[$i] = $box[$j];
			$box[$j] = $tmp;
		}
		
		for($a = $j = $i = 0; $i < $string_length; $i++) {
			$a = ($a + 1) % 256;
			$j = ($j + $box[$a]) % 256;
			$tmp = $box[$a];
			$box[$a] = $box[$j];
			$box[$j] = $tmp;
			$result .= chr(ord($string[$i]) ^ ($box[($box[$a] + $box[$j]) % 256]));
		}
		
		if($operation == 'DECODE') {
			if((substr($result, 0, 10) == 0 || substr($result, 0, 10) - time() > 0) && substr($result, 10, 16) == substr(md5(substr($result, 26).$keyb), 0, 16)) {
				return substr($result, 26);
			} else {
				return '';
			}
		} else {
			return $keyc.str_replace('=', '', base64_encode($result));
		}
		
	}
	
}